This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Lunar dust has raised issues for space exploration ever since the Apollo missions. Its unique adhesive and abrasive properties make it a hazard for space suits materials, life support systems and astronaut health. With NASA?s program for returning to the Moon, the concerns for the lunar dust as a factor affecting human exploration of the Moon have become pressing. Lunar dust contains iron with toxic potential. The fruit fly Drosophila can be used as a biological sensor to measure the iron toxicity of lunar dust. Fruit flies carrying the human gene responsible for the Huntington?s neurodegenerative disease are sensitive indicators of the toxicity of iron. Synchrotron radiation is uniquely suitable for refined elemental analysis of small living specimens. X-ray fluorescence spectroscopy can be used to localize the deposition of iron into fruit fly tissues and to obtain spectra to speciate iron in situ. The long-term goal is to develop the fruit fly as a sensor the toxicity of lunar dust to be available for a science payload on a future lunar mission. This would allow measuring the toxicity of lunar dust in vivo on the surface of the Moon and test countermeasures to mitigate its toxic effects. The objective of this project is to provide fundamental insight into the geochemical properties and toxicity of lunar dust by using x-ray fluorescence spectroscopy and elemental mapping to determine the incorporation of iron from lunar dust into living tissues.